1. Field of the Invention
The present invention relates to a cleaning apparatus having a plurality of tanks including a cleaning tank.
2. Description of the Prior Art
As is well known in the art, workpieces such as precision mechanical parts, electronic parts, or the like are cleaned by cleaning apparatus in various cleaning processes including an ultrasonic cleaning process, an ultrasonic rinsing process, and a drying process depending on the type of workpieces to be cleaned and the degree of accuracy to which they are to be cleaned. The cleaning apparatus have tanks in which the respective processes are carried out. To clean and rinse a workpiece with a cleaning apparatus which has an ultrasonic cleaning tank and an ultrasonic rinsing tank, for example, the workpiece is horizontally slidably supported by a support disposed above the ultrasonic cleaning tank, and then lowered into the ultrasonic cleaning tank. After the workpiece is cleaned in the ultrasonic cleaning tank, the workpiece is lifted up to the original position above the ultrasonic cleaning tank. Then, the workpiece is transferred to a position above the ultrasonic rinsing tank, and horizontally slidably supported by a support disposed above the ultrasonic rinsing tank. Thereafter, the workpiece is lowered into the ultrasonic cleaning tank in which it is rinsed. In this manner, the workpiece is cleaned and rinsed by the cleaning apparatus.
In the cleaning apparatus, the ultrasonic cleaning tank and the ultrasonic rinsing tank are integral with each other. Such an integral tank arrangement suffers the following difficulties:
Sometimes, it is necessary to replace one of these tanks with another tank in view of the type of workpieces to be cleaned and the degree of accuracy to which they are to be cleaned. However, since the ultrasonic cleaning tank and the ultrasonic rinsing tank are integral with each other, all the tanks have to be replaced even though only the replacement of one tank is required. This is more costly than necessary. In the event of a failure of one of the tanks, e.g., the ultrasonic cleaning tank, the entire cleaning apparatus needs to be shut off until the ultrasonic cleaning tank is repaired. Even when the type of workpieces to be cleaned and the degree of accuracy to which they are to be cleaned requires the addition of another processing tank or make one of the existing tanks unnecessary, such another processing tank cannot be added or the unnecessary tank cannot be removed. If another processing tank is additionally needed, the existing cleaning apparatus has to be replaced as a whole with a new cleaning apparatus which includes such another processing tank integral with other tanks. As a consequence, cleaning workpieces of different types or to different degrees of accuracy necessitates different types of cleaning apparatus, resulting in a large expenditure of money for an investment in the equipment.
When a workpiece is ultrasonically cleaned, an ultrasonic energy is radiated from below the workpiece and applied to the workpiece. Therefore, the workpiece should be supported by a support such that the bottom of the workpiece will not be covered by the support.